Measurement of residual stress in multicrystalline silicon ribbons by a self-calibrating infrared photoelastic method

Abstract

This article reports on a method for the measurement of residual stress in multicrystalline silicon ribbons, based on the infrared photoelastic technique. This self-calibrating method allows the in situ determination of the photoelastic coefficients and can thus be used for any crystal orientation. The method was validated by the experimental determination of the photoelastic coefficient of monocrystalline (100) silicon wafers and by comparison with strain measurements using asymmetrical x-ray diffraction. The distribution of residual stress in multicrystalline silicon ribbons was also measured. The results showed strong evidence for tensile stress in the central region and compressive stress near the edges of the ribbons. Both the measured residual stress and the photoelastic coefficient distributions are correlated to grain boundaries.

Applied Photoelasticity for Residual Stress Measurement inside Crystal Silicon Wafers for Solar Applications

“…In full knowledge of this phenomenon, a generalised opticoelastic coefficient has been applied on the full field of the polycrystalline wafers to assess the level and the distribution of the residual stress inside polycrystalline silicon wafers. This generalisation is also present in the literature [2] [30]. The opticoelastic coefficient has been fixed at 16.10 À12 Pa À1 by He et al [31].…”

“…The optical and mechanical behaviours variation in the thickness of the wafers can be assumed negligible and bi‐dimensional measurement can be appropriate to measure bi‐dimensional residual stresses. Few works has been already made on the residual stress measurement in silicon crystal by bi‐dimensional photoelasticity . These results reveal the influence of the mechanical anisotropy of the silicon and predicted a very low level of residual stresses.…”

Analysis and comparison of different methods used to extract isoclinic and isochromatic parameters. Application to the determination of the residual stresses inside crystal silicon wafers

“…In order to determinate the residual stresses inside crystal silicon wafers, the authors of the literature commonly used the Wang and Patterson [3,13] and the Ashokan and Ramesh [14] methods to extract the isoclinic parameter whereas the maximal shear stress are quantified using the Wang and Patterson, [3,15] the Ashokan and Ramesh, [14] and the Quiroga [16] methods.…”

Stress evaluation of Through-Silicon Vias using micro-infrared photoelasticity and finite element analysis

“…In contrast, the advantage of photomechanics methods based on optical interferometry is that it is more fitted to failure analysis and reliability evaluation during thermal loading [8]. As a typical photomechanics method, photoelasticity (PE) has already been applied to stress evaluation of a silicon chip [9,10], although no characterization for the stresses of a TSV structure was found. In these limited applications, infrared (IR) light with wavelength over 1150 nm must be employed because visible light cannot pass through the silicon chip, more details about the transmittance of a silicon wafer to infrared light and the photoelasticity (IRPE) technique can be found in Ref.…”